Photographic product comprising a sheet support and means for collecting liquid spread upon said support in excess of that required to cover a predetermined area of the support



Aug. 17, 1954 LAND 2,686,717

PHOTOGRAPHIC PRODUCT COMPRISING A SHEET SUPPORT AND MEANS FOR COLLECTING LIQUID SPREAD UPON SAID SUPPORT IN EXCESS OF THAT REQUIRED TO COVER A PREDETERMINED AREA OF THE SUPPORT Filed April 16, 1949 2 Sheets-$heet l INVENTOR t mwg iw Aug. 17, 1954 E. H. LAND 2,686,717

PHOTOGRAPHIC PRODUCT COMPRISING A SHEET SUPPORT AND MEANS FOR COLLECTING LIQUID SPREAD UPON SAID SUPPORT IN EXCESS OF THAT REQUIRED TO COVER A PREDETERMINED AREA OF THE SUPPORT Filed April 16. 1949 2 Sheets-Sheet 2 LIIIAVIIIII,

INVENTOR Patented Aug. 17, 1954 PHOTOGRAPHIC PRODUCT COMPRISING A SHEET SUPPORT AND MEANS FOR COL- LECTING LIQUID SPREAD UPON SAID SUP- PORT IN EXCESS OF THAT REQUIRED TO COVER A PREDETERMINED AREA OF THE SUPPORT Edwin H. Land, Cambridge, Mass., assignor to Cambridge, Mass, a cor- Polaroid Corporation poration of Delaware Application April 16, 1949, Serial No. 87,912

24 Claims. 1

This invention relates to photography and more particularly to novel sheetlike photographic products releasably carrying a photographic processing liquid for producing a predetermined processing of an exposed photosensitive material by spreading of said liquid across a surface of said photosensitive material, said products including liquid-- spreadingsurfaces. This application is in part a continuation of my copending application Serial No. 641,310, filed January 17, 1946 (abandoned in favorof application Serial No. 161,414, filed May '11, 1950, and now matured into Patent No.

2,627,460); is in part a continuation of my 00-, pending application Serial No. 668,158, filed May 8, 1946 (now Patent No. 2,500,422); and is in part a continuation of my copending application Serial No. 782,117, filed October 25, 1947 (now Patent No. 2,579,587).

In my copending application Serial No. 87,911, filed on even date herewith there is described a photographic product including a sheetlike liquid-confining layer and comprising, arranged in order along said product, a liquid-containing portion, an image area portion and a liquid-trapping portion, the product being arranged so that the liquid, prior to use of the product, is confined in a relatively thick layer of small area in said liquidcontaining portion and. is arranged to be spread from said liquid-containing portion in a relatively thin layer across said image area portion and all the excess liquid is confined in a relatively small area in the liquid-trapping portion. In a product of the above type two liquid-confining layers are preferablyprovided, one of these layers in cluding a photosensitive portion, and the liquidcontaining portion of the product is arranged to trapping portion.

Another object of the invention is to provide a product of the above type which is simple to Still another object of the invention is to provide a product of the above types wherein the image area is readily separable from the remainder of its liquid-confining layer.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the product possessing the features, properties and the relation of components which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understandnig of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

Figure 1 is an exaggerated diagrammatic isometric view of one preferred product of the invention with parts thereof cut away for clarity of illustration;

Fig. 2 is an exaggerated diagrammatic enlarged sectional view of the film unit of Fig. 1 showing the relationship of the elements thereof during use of the film unit;

Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken alongthe line i i of Fig. 2;

Fig. 5 is a diagrammatic exaggerated enlarged isometric view of another modification of the invention;

Fig. 6 is a View similar to Fig. 3 showingthe operation of the product of Fig. 5;

Fig. 7 is a view similar to Figs. 3 and 6 showing the operation of still another modification of the invention; and

Fig. 8 is a view similar to Figs. 1 and 5 showing still another form of the invention.

In general this invention relates to a novel photographic product containing all of the material, including a photographic reagent, in the amount required to produce a transformation of image, in the product itself,or in a photosensitive layer portion brought into superposed relationship with the product. The product preferably is in the form of a film unit comprising a first liquid-confining layer, including a photosensitive manufacture and use and which is particularly effective for trapping excess liquid when the liquid is spread between the liquid-confining layers by means of a pair of pressure-applying members, at least one of which is resiliently mounted or has a resilient surface.

portion capable of having an image formed therein upon photoexposure, and a second liquid-confining layer superposahle with the first liquidconfining layer. The product includes, arranged in order along said product, a liquid-containing portion, an image area portion and a liquid-trapping portion. The liquid-containing portion pref erably comprises a rupturable container holding a viscous processing liquid. The viscosity is preferably quite high and is preferably obtained by the use of a thickening agent, a preferred type of thickening agent comprising a dispersion, preferably a solution, of a film-forming colloid, such as a film-forming plastic, protein, or carbohydrate. This liquid is in excess of the minimum amount required for producing the above-mentioned transformation of an image formed by photoexposure of the photosensitive portion. The container is arranged for releasing its contained liquid between the two liquid-confining layers adjacent one edge of the image area in position to be spread across this image area between the two liquid-confining layers in a layer of, a predetermined optimum thickness.

In a film unit of this type the release and spreading of the released liquid is preferably accomplished by passing the film unit between a pair of pressure surfaces, such as a pair of pressure rolls, for example. Since it is desirable that the film unit be usable under extremely widely varying conditions of temperature, humidity and other varying characteristics, which may create irregularities in the release of the liquid from the container or in the actual spreading thereof, it

is desirable to include in the container more liquid than the absolute minimum required for covering just the image area to the predetermined depth of liquid. The passage of the film unit between a pair ofpressure rolls, for example, also poses the problem of nonuniform release of the liquid from the container due to the possibility of nonuniform rupture thereof. During the spreading of the liquid there is nonrectilinear distribution of the liquid as the quantity of liquid being spread decreases. This results in a spread which, during the initial part thereof, tends to expand towards the edges of the superposed layers and, during the latter part of the spread, tends to contract to a narrow tongue near the centers of the superposed layers. In the present invention there is provided an ample amount of liquid in the container so that the tongue of liquid does not contract sufiiciently in the image area of the product so as to leave any of the image area uncovered. Thus there is enough liquid to assure a complete coverage of the image area with a predetermined layer of liquid. This amount of liquid is preferably suflicient to give complete coverage even under adverse conditions of temperature and humidity and even allowing for some maldistribution of the liquid due to nonuniform rupture of the container.

The present invention is primarily directed to the provision of a film unit of the type described above wherein the excess liquid initially provided is neatly trapped between the two liquid-confining layers so that it does not contact any of the spreading members in a camera, for example. The present invention, in a preferred form, also traps the excess liquid so that it is not readily contacted by the user of the camera after processing of the photosensitive material. When the individual film unit is a part of a longer photographic product, comprising a plurality of sequentially arranged containers, image areas and trapping portions, the trapping portion of the present invention also prevents passage of liquid, used for processing one image area, onto the succeeding image area.

In the present invention the trapping portion of the product broadly comprises portions of the two liquid-confining layers which, when superposed, define therebetween a volume in which the excess liquid may be confined in a layer thicker than the predetermined layer in the image area portion. This volume in the trapping portion is at least as great as the difference between the 7 volume of liquid to be spread in the predetermined. layer in the image area portion and the volume of liquid initially held by the container. In a preferred arrangement of the product the trapping portion comprises at least one member carried by one of the two liquid-confining layers and arranged so that, when these layers are superposed and the resulting product is pasesd between a pair of pressure-applying surfaces, these pressure-applying surfaces are moved apart during passage of the trapping portion therebetween. This trapping member is preferably smaller than the area of the trapping portion and arranged so that it is positioned between the facing surfaces of the two liquid-confining layers when these layers are superposed. By means of this arrangement the inner surfaces of the layers in the trapping portion are held spaced apart farther than the inner surfaces of these layers in the image area portion during the passage of the product between a pair of liquid-spreading surfaces and that portion of the resulting space not filled by the trapping member serves as the liquid-confining space.

Referring now to Figure 1, there is shown one preferred modification of the invention wherein the product preferably comprises the two liquidconfining layers, one of these two layers including the photosensitive portion. In this modification the trapping portion of the product .comprises a pair of trapping members secured to that surface of one of the liquid-confining layers which is to be brought into face-to-face relation with the other liquid-confining layer. These two trapping members are preferably relatively incompressible and occupy a relatively small percentage of the area of the trapping portion. Each of the trapping members has a dimension normal to the liquid-confining layer which is considerably greater than the thicknses of the liquid layer to be spread across the image area.

In Figure 1 the two liquid-confining layers are shown at H! and i2, these liquid-confining layers ill and 42 preferably being portions of longer layers including a plurality of individual film units. Liquid-confining layer Iii preferably comprises a suitable base l4 carrying a photosensitive emulsion layer it on one surface thereof. This photosensitive layer preferably comprises a silver halide and has an area i600 thereof adapted to be exposed to actinic light for the creation therein of a latent negative image. The liquidconlining layer l2 preferably comprises a base 13 carrying an image-receiving layer 211 on one surface thereof. The image-receiving layer 20 has a predetermined surface area 22 thereof which is particularly adapted to receive a positive image of the latent negative image formed by exposure of the photosensitive image area lea carried by liquid-confining layer Hi. This positive image area 22 is preferably outlined by a plurality of perforations 2 extending through the layer [2 so as to be separable from the remainder of the liquid-confining layer i2. For initiating removal of image area 22, by tearing this image area from the remainder of the layer, there is provided a tear-out hole 25, this tear-out hole preferabl extending completely through the layer i2.

When the two liquid-confining layers 10 and I2 are superposed they form a product having, arranged in order along the product, a liquid-conaescgvrw taining. portion,. ani image. area. portion. and. a 111- quid trapping portion. The: liquid-containing portion preferably comprises a container 26, shown. as being. secured: to the liquid-confining layer l2,.over1ying the. tear-out hole 25. Con tainer. 26. ispreferably collapsible, being: formed oil a flexible-walled liquid-impervious. material, being sealed at the ends and having a: sealed. liquid-releasing mouth or, lipu28 along that edge of the container which is closest to the adjacent edge" of theimage area 22. The container 26 preferably includes a predetermined quantity ofa viscous processing liquid 30, a preferred type of liquid comprising a viscous aqueous alkaline solu; tion of an organic.film+forming.material,.a silver halide developer and a silver halide solvent. The trapping portion of the product shown in Fig- 1 comprises a pair of relatively. incompressible members 32 secured to the surface of the imagereceiving layer 20 adjacent the margins thereof; These members are preferably quite narrow, with respect to the transverse dimension of the trapping. portion, the space between these trapping members 32 being indicated at 34 and providing thetrapping volumein which the excessliquid 30 is confined. I

In Fig. 1- the approximatepath, with relation to the above-identified elements, followed by the liquid 30 during release andspreading thereof, is-=shown by the dotted 1ines30a. As can be seen, this .path starts out from the container mouth 28 with a width about equal to the width of the image area 22; as defined by the longitudinal perforation lines: The liquid then spreads out towards the edges of the layer [2 and the outer limits of theliquid spread lie between the longitudinal perforations 24 and the edgesof' the liquid-confining layer l2. When the liquid has been spread sufiiciently far along the product so as to completely coverimage area 22" the width of the liquid spread commences to decrease so that all of the excess thereof passes into thespace 34 existing between the two trapping members 321 The actual mechanics of spreading andtrapping of the liquid. are shown best in Figs. 2, 3 and 4, these figures being enlarged exaggeratedsectional. viewsof the Fig. 1' modification of the invention during the use thereof; In these figures; likenumbers correspond tolike elements of the other figures. During the processing of an indi-- vidual film unit included within the product of the present invention, the predetermined image area I Ba of thephotosensitive layer-l6- is first ex posed'ina suitable manner, such as in a camera. The exposed photosensitivelayer lii 'is then superposed with the iinage' receiving layer Zilso that the exposed area I 6a coincideswith the image area 22. The two superposed liquid-confining layers Hland'lZ, withxthe container 25 therebetween, are'then passed between a pair ofpres sure-applying: surfaces to cause therelease andspreadingof the 1iquid30'fbetween' thefaoingsurfaces of' these two" superposed liquid-confining layers. The pressure-applying surfaces prefer-- ably act to superpose the two liquid-confining layers andfare shown in their preferred'form as a pair of pressure rol1s35 and 38; These rollspref erably-are so arranged that, during the spreading of: the liquid'across theimage area portionof the, product, these rolls have what: amounts toa predetermined fixed gap therebetween'. However, the rolls-- are also. arranged. so I that they. may readily separateduring passage of the trapping portion therebetween. During spreading of the: liquid-,across the :image. area the: fixed gap be-- image" area portion ofthe product. taining this fixed gapthe axle 44 is normally held. in contact with the upper end of the slot.

maintain therroll =38 in the positionshownisothati inglayers IO and l2 by anamounton theorder' of the thickness'desired for thelayer of liquid; 301:0 be spread between the facing surfaces of the photosensitive layer I6 and image-receivinglayer 20; When a silver image is to be formed on the surface: of: the image-receiving layer 20 it is desirable to spread a layer of. the liquid'30 having a: wet thickness on-the order'of about .002 inch.

With one preferred type of liquid composition this gives a dry thickness on the order of 10001 to .0003 inch. The design anddimensions of the various suitable pressure-applyingsurfaces for giving such a predetermined thickness of spread arediscussedmore fully in the copending application of Edwin H. Land, Murry N. Fairbank and.

Davis S. Grey, Serial No. 0, 4; filed December 6, 1947 (now PatentNo. 2,483,014).

Due to the fixed gap arrangement of the pressure rolls-36 and 38, the liquid 30, released from the container mouth 28, is spread between the facing. surfaces of the photosensitive layer 16'- and the image-receiving layer ZD-ina layer of a predetermined fixed thickness. pingportion of the product passes between rolls 36and 38there is defined between liquid-confininglayers l0 and I2 a greater volume per unit area than existed in. the image area portion of This is due to the fact that the the product. increased thickness of the trapping portion of theproduct, created by the presence of the trapping members 32, causes the pressure rolls to separate considerably more than the fixed gap Which existed when the liquid was being spread across the image. area portion. This separation of the pressure rolls permits the inner facing surfaces of layers iDand 2fl'to separate by substantially. the same amount, thereby providing a large spacefld in which the 1iquid 30 is'confined-ina relatively thick layer. This separation of the layers I01 and E2 in thetrapping portion accordinglyallowsallof the excess liquid to be confined in a relativelysmall area of the product, thereby resultingtin a saving of. materials and preventing escape of." the liquid.

Examination ofFig. 3 shows the transverse distribution of the excess liquid in the trapping. space 34'; Figs. 3' andialso show a preferredarrangement of the mounting for. the pressure rolls 36 andSB' so that: at least one of the rolls can move awayfrom the other roll under a high pressure generated between the rolls. One preferred type of. such: mounting. for the two. pressure rolls l comprises a bearing'block 40 adapted. to receive axles i2 and 44 associated, respectively, with rolls 36 and 38. Axle 44 is carried in a slot 46 in bearing block 48. In Fig. 3 the axle M is shown as being positioned about in the middle of slot 46, while in Fig. iaxle M is shown as being flush with the upper end of the slot 46. Fig. 3 thus shows the position of'the axle when the trapping portion of the' product is passing between the pair of pressure rolls and Fig. 4 shows the position of the axle whenthe-image'area portion of the product ispassing between'lthepressure rolls. Fig; 4shows the position of the axle which gives the fixed gap desirable during the spreading across the For maine 'i by means of a bearing member 48 which urges 50. Thus the slot 46 and the spring 50 normally When the traprolls 36 and 38 are spaced apart a predetermined fixed amount during the spreading of the liquid. However, spring 50 can be compressed when the pressure generated between the rolls increases considerably. The pressure necessary to move the roll 38 against the force of spring 50 is preferably quite a bit greater than the pressure generated in the liquid so that, for spreading purposes, these rolls may be considered to have a fixed gap. This arrangement is such that when the relatively incompressible trapping members 32 pass between the pressure rolls they readily separate these rollsby an amount sufficiently greater than the fixed gap to accomplish the trapping function.

Fig. 4 also illustrates an important characteristic of the viscous liquid which permits elimination of edge leakage when the edges of the two liquid-confining layers l and [2 are not sealed together. Prevention of this edge leakage is accomplished by relieving the end portions of the rolls 35 and 38 which engage the marginal portions of the liquid-confining layers [0 and I2. This arrangement of the pressure rolls relieves the pressure at the magins of the two layers 10 and I2 so that any transversely flowing liquid existing between these marginal portions is thus relieved of its pressure. The release of the pressure is sufficient, due to the viscosity of the liquid, to prevent any further tendency on the part of this portion of the liquid to flow transversely of the product. The marginal portions of the liquid, therefore, are held inwardly of the edges of the two liquid-confining layers I0 and I2 and are confined between these two layers. It should be pointed out that this method of preventing this edge leakage additionally requires the use of an excess amount of liquid in the container over that which would ordinarily be required to just cover the image area 22 to the predetermined desired thickness of spread liquid.

In preferred forms of the invention the various elements preferably comprise materials stated as being preferable in my copending application Serial No. 7,795, filed February 12, 1948 (now Patent No. 2,647,056). In one preferred form of the invention the photosensitive layer I6 comprises a Example 1 Baryta paper is run through a bath which is kept in contact with the baryta surface for approximately ten second, the bath comprising:

Cadmium acetate grams 9 Neutral lead acetate do .3 Zinc nitrate do 18 Water cc 100 The sheet thus obtained is dried and coated with a mixture comprising:

Water cc 270 Cadmium acetate grams 27.8 Lead acetate do 9.3 Zinc nitrate do 55. Silica aerogel (Santocel C) do 3% water solution of sodium sulfide cc 94.7

The sheet is preferably dipped into this mixture and the excess mixture is removed from the sheet ingredients listed in the following nonlimiting example Example 2 A processing agent is preparedwhich comprises:

Grams Water 1860 Sodium carboxymethyl cellulose 117 Sodium sulfite 78 Sodium hydroxide 74.6 Sodium thiosulfate 14.5 Citric acid 38.5 Hydroquinone 2 The processing agent is prepared by dissolving the sodium carboxymethyl cellulose, for example the commercially available Hercules 1362 medium viscosity type, in the water in a mixer at room temperature, and the solution is mixed therein for approximately one hour. Thereafter, the sodium sulfite, sodium hydroxide, sodium thiosulfate and citric acid are added to the solution, the addition being effected in an inert atmosphere, for example of nitrogen. Upon dissolution of these materials, the hydroquinone is added and the solution is further mixed for an hour at approximately room temperature in a nonoxidizing atmosphere of nitrogen.

In one preferred form of the invention the baryta paper [2 is a single weight baryta paper approximately .006 inch thick and the trapping member 32 comprises a paper tape having a pressure-sensitive ladhesive coating, the tape being approximately .018 inch thick. It can thus be seen that the trapping member 32 is somewhat thicker than the baryta paper and is approximately 9 times as thick as the .002 inch wet thickness of the layer of liquid to be spread across the image area of product. v

The liquid described in Example 2 has a viscosity of approximately 20,000 centipoises at 20 C. As discussed in the last-named copending application, this voscosity may be considerably less than 20,000 centipoises. However, for best control of spreading and optimum functioning of the liquid-trapping portions, a viscosity in excess of 1,000 centipoises is preferred. The container 26 preferably comprises a paper-backed lead foil having an inner coating of polyvinyl butyral and having a stronger end seal than the seal alon the mouth 28 thereof.

When the liquid of Example 2 is spread between the exposed silver halide emulsion layer and the image-receiving layer of Example 1 the developer develops exposed silver halide grains in the emulsion. Concurrently therewith, the silver halide solvent forms soluble complexes with the undeveloped silver halide grains and transports these complexes to the surface of the image-receiving layer where the complexes are converted to silver by the joint action of the developer and the elements provided in the treatment of Example 1. At the end of about a minute or so, depending upon the particular ingredients involved, the user of the product can remove the processed image area 22 by inserting a fingernail through the hole 25 and tearing out positive image area 22 along the perforation lines 24, thereby another form of the invention which is particularly useful in a camera of the type described above employing a pair of pressure-applying members, at least one of which has a resilient surface. In this form of the invention the trapping portion comprises a plurality of trapping members mounted in transversely spaced relationship on one of the liquid-confining layers in the trapping portion thereof. In Figs. 5 and 6 like numbers refer to like elements in the other figures and the trapping portion is indicated generally at 54 as comprising a member having a plurality of spaced tongues 56 extending towards the image area 22. These tongues 56 act as the trapping members and define therebetween a plurality of spaces 58 which, in the aggregate, make up a sufficient volume to trap all .of the excess liquid 30 therein. In Fig. 6 the operation of this modification of the trapping portion is shown with respect to a pressure roll 5!! having a resilient surface, this pressure roll being used in lieu of the pressure roll 38 in the preceding figures. One preferred mounting for such a roll comprises a bearing block 62 in which the axle 44, associated with roll 38, and the axle 64, associated with the roll 50, are fixedly mounted against movement away from or towards each other. In this form of the invention the various tongues 56 of the trapping portion compress the resilient portion of the roll 66 sufficiently so that the space between the bottom of roll 60 and top of roll 38 is considerably increased during passage of the trapping member 54 between these rolls. Due to the fact that the roll 60 is resilient, the distance between facing surfaces of layers l and [2, in the middle of spaces 58, is not quite as great as the distance between these layers in contact with the tongues 55. However, the distance between these facing surfaces is sufficient to allow the various spaces 58 to have a total volume adequate for trapping all of the excess liquid. It should be apparent that, other conditions being identical, the thickness of tongues 56 in the Figs. and 6 modification should be greater than the thickness of the two trapping members 32 of the Fig. 1 modification of the invention.

Referring now to Fig. '7 there is shown still another modification of the invention, which is similar to the Fig. 1 form thereof, but wherein the trapping members are positioned on the back of one of the liquid-confining layers, 1. e. on that surface thereof opposite the surface to be brought into face-to-face superposed relation with the other liquid-confining layer. In this figure, where like numbers refer to like elements in the preceding figures, one of the trapping members is indicated at 10. This trapping member 10 has the same roll-separation function as the trapping member 32 shown in Fig. 3. However, the liquid-confining space indicated at 12, which is formed as a result of the roll separation, is created at least partially by the liquid pressure within the liquid-confining space 12. Consequently, the Fig. 7 modification of the invention is not quite as efiicient in its trapping function as is the Fig. 7 form, other conditions being the same. liquid-confining layer, which carries the liquidtrapping member 10, must be flexible so as to be easily deformed to provide the liquid-trapping space 12 under relatively low liquid pressure.

It should be also pointed out that the However, this form of the invention has the advantage that the trapping member 'lii, being on the back surface, may be utilized for operating a film-positioning sto for predeterminedly locating portions of the product with. respect to the exposure aperture, or the pressure rolls, for example.

Referring now to Fig. 8 there is shown still another modification of the invention wherein the trapping member comprises a porous material positioned on that surface of, and extending above that surface of, one of the liquid-confining layers is to be brought into face-to-face relation with the other liquid-confining layer. This porous material is made so as to have a sufficient volume and resistance to compression as to provide the liquid-confining volume under compression during passage between the pressure rolls. In Fig. 8, where like numbers refer to like elements in the preceding figures, the trapping member is indiciated at it, this trapping member being, in this case,'preferably substantially co-extensive with the trapping portion of the product. While the physical volume of the trapping member 16 is substantially equal to the volume of the trapping portion, its solid volume isrnade less than its physical volume by an amount adequate to provide the liquid-confining space, even under compression. A preferred porous material for forming a trapping member of the type shown in 16 comprises a heavy crisp gauze, preferably being several layers thick and including a sizing to increase its stiffness. Such a gauze is capable of withstanding considerable compression without losing its ability to confine the excess liquid within its interstices. The Fig. 8 modification of the invention is particularly useful in those forms of the invention wherein the liquid 30 has a relatively low viscosity.

In the discussion of the various drawings, the liquid-confining layer I 0 has been described as carrying the photosensitive portion, this being the preferred form when a positive silver image is to be created in the image area 22 since the image area, after processing, may be removed from the two superposed layers, thus leaving the trapped liquid between these two layers. However, the photosensitive portion may be carried by layer :2 instead of bylayer It. Equally it is quite possible for both layers I tend l2 to include photosensitive portions, as described in my copending application Serial No. 729,579, filed February 19, 1%? (now Patent No. 2,565,376).

In any or all of the various above-described modifications of the invention, the trapping efiiciency of the trapping portion may be improved by including in said trapping portion, in position to be dissolved by the liquid, an insolubilizing agent capable of insolubilizing the film-forming material which is preferably included in the processing liquid for increasing the viscosity thereof. Such an insolubilizing agent is par ticularly helpful in forms of the invention wherein the image area is inseparable from the lamination formed of the two liquid-confining layers and the spread layer of liquid. In such a case the removal of the processed image area may expose the thick layer of trapped liquid which, due to its high volume to surface ratio, may still be quite wet even though the image area portion of the spread liquid is completely dry. This may permit the liquid to be accidentally wiped off by the users clothing or fingers, a rather undesirable occurrence. However, the irisolubilizing agent converts the mass of trapped liquid to a relatively solid gel which does not readily stick to the users clothing or hands if accidentally contacted thereby. This insolubilizing agent may also serve the function of preventing the trapped liquid from slowly seeping out of the trapping surface in the event that the camera, for example, in which this product is used is so positioned that that plane of the pressure rolls is horizontal.

The degree of gelation of the mass of trapped liquid in the trapping portion depend upon a number of factors, such as the rate of the insolubilizing reaction, the concentration of the insolubilizable film-forming material in the liquid, the concentration and solubility of the insolubilizing agent in the trapping portion and the porosity of the trapping portion to water or other solvent for the film-forming material.

The insolubilizing reagent may take a number of forms depending upon the film-forming organic colloid employed. Where, for example, the film-forming material comprises. sodium carboxymethyl cellulose the insolubilizing reagent preferably comprises an amphoteric polyvalent metal salt. This salt is also preferably capable of lowering the high pH, preferably employed with the developer, or is present along with an acid for accomplishing this neutralization. Examples of such salts are lead salts, such as the acetates and nitrates which are readily soluble, zinc nitrate, aluminum chloride, stannous chloride and others. The lead salts are particularly preferred since they form what appears to be a cross-linked three-dimensional plastic. One convenient way of applying these salts to the trapping portion of Fig. l, for example, is to coat the upper surface of layer 20 with a relatively high concentration of these salts, such as by passing only the trapping portion of this surface in contact with a bath containing 40% by weight of lead acetate, for example. It is apparent that the high concentration of the insolubilizing reagent may be applied in numerous other ways such as by spraying, painting, printing, etc. When a porous material is additionally included in the trapping portion it may be dipped in a bath of the insolubilizing reagent before being applied to the film construction, the reagent being preferably so situated as not to decrease the porosity of the absorbent material.

Other film-forming materials which can be used are, for example, the sodium salt of polymethacrylic acid, the sodium salt of cellulose acetate hydrogen phthalate, sodium carboxymethyl cellulose having a degree of substitution of about 0.3 to 0.4 carboxymethyl groups per glucose unit and hydroxyethyl cellulose having less than about 0.5 combined ethylene oxide per glucose unit. These salts are such that their solubility decreases markedly when the pH drops below about 7. To insolubilize these materials an acid, such as maleic acid, or an acid salt, such as stannous chloride, may be incorporated in the trapping area to neutralize the alkali in the liquid and lower the pH below '7, thereby rendering these film-forming materials relatively insoluble. With the polymethacrylic acid salt the metal ion may additionally act to replace the sodium ion and thus give a three-dimensional plastic. When a plastic such as polyvinyl alcohol is used as the film-forming material, this being feasible where the developing agent, i. e., hydroquinone, is included in dry form in one of the liquid-confining layers, the insolubilizing reagent may comprise a number of materials such, for example, as sodium sulfate, sodium chloride, potassium chloride, and potassium sulfate.

While specific preferred forms of the invention have been shown in the drawings and discussed in connection therewith it should be manifest that numerous modifications may be made in the physical relationships of the various elements, as well as in the chemical processes involved, without departing from the scope of the invention. The photosensitive material may comprise numerous substances other than a silver halide such, for example, as a dichromate, a diazonium compound and others. The spectral response of the photosensitive material may range from the radiation associated with radium and X-rays to the infrared. Various portions of the liquidconfining layers may be opaque or transparent, depending upon the sensitivity of the photosensitive materials, the method of exposure and the handling thereof after exposure and during processing. For example, if the exposure and processing of the photosensitive emulsion is carried out completely within a camera both of the liquid-confining layers may be transparent. In this form of the invention the edges of the liquidconiining layers extending between the container and liquid-trapping portions of the product are preferably sealed together. This form is desirable in a number of instances such, for example, as the processing to obtain positive projection transparencies. Various other degrees of transparency or opacity may be employed to fit the requirements. of any particular case.

While several specific examples of preferred processes for obtaining positive silver images have been illustrated, numerous modifications thereof may be practiced. For example, only a portion of the processing reagents need be included in the liquid, it being feasible to place a number of these reagents in or on either of the two liquid-confining layers l0, H! in dry form. Additionally, the processes may be directed to developing a negative rather than for the formation of a positive.

A number of other image-forming and imagetransfer processes which may be used with the above-described invention are described in my above-mentioned copending application Serial No. 7,795, filed February 12, 1948. a

The various products of the present invention have been shown in the form of two sheets, one of which carries the container and the trapping member. It should be apparent that one sheet, for example the liquid-confining layer It, may carry the container while the other sheet, for example liquid-confining layer 12, may carry the trapping member. This is particularly true when the arrangement is such that these sheets, are either used. in their superposed relation or are so related to each other that they may be readily and accurately superposed during processing. The two sheets may be separately rolled into two rolls, with the outer ends thereof connected, so that two sheets can be fed from their two rolls into predetermined superposed relation, this being a preferred arrangement of the invention. However, it is equally possible for the two liquidconfining layers to be superposed in the form of a single unit and sealed at the edges. As explained previously, this modification is particularly useful when one or both of the layers is relatively transparent to the radiation used to expose thephotosensitive material.

Since certain changes may be made in the above 13 product without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A photographic product comprising a sheet support, a rupturable container holding a liquid, said container being mounted on one surface of said support to extend transversely of said surface for spreading of its liquid content lengthwise of .said surface upon rupture of the container, said surface having said container mounted thereonbeing provided with an area which. extendsfrom said container lengthwise of said support for a predetermined distance and over which liquid from said container is adapted to be spread, saidliquid being in a quantity more than sufficient to cover said area upon rupture of said container and the spreading of said liquid upon said surface, said sheet support having a part thereof which extends said surface beyond the end of said area furthest removed from said container to provide a portion on said surface for receiving liquid in excess of that needed to cover said area, at least one difficultly compressible member mounted onone surface of said sheet support at a position thereon so that said difiicultly compressible member and the excess liquid-receiving portion are in superposed relation, said difficultly compressible member extending outwardly from the surface on which it is mounted and occupying an area thereon which is smaller than i the area of said excess liquidreceiving portion, means being provided by said difficultly compressible member whereby pressure applied transversely of said sheet support to opposite surfaces thereof at that part of said sheet support which includes said excess liquidreceiving portion is transmitted substantially only to said difiicultly compressible member and a partof said sheet support in superposed relation to said difiicultly compressible member.

2. A photographic product as defined in claim 1 wherein said difficultly compressible member is mounted on that surface of said sheet support which carries said rupturable container.

3. A photographic product as defined in claim 1 wherein said difiicultly compressible member comprises a porous material absorptive of liquid within said container and wherein said member is located on that surface of said sheet support upon which said rupturable container is mounted.

4. A photographic product as defined in claim 1 wherein a plurality of difficultly compressible members are mounted upon that surface of said sheet support which carries said rupturable container, said difiicultly compressible members being located on said surface in spaced-apart relation and transversely of said support.

5. A photographic product as defined in claim 1 wherein a pair of difiicultly compressible members are positioned adjacent the margins of said sheet support on that surface of said support which carries said rupturable container.

6. A photographic product as defined in claim 1 wherein a pair of difficultly compressible members are secured to that surface of said sheet support which is opposite the surface upon which said container is mounted.

7. A photographic product comprising an elongated sheet support, a plurality of rupturable containers, each having aliquid-releasing mouth and each holding a liquid, said containers being mounted on one surface of said support in spaced relation lengthwise of said support and eachcontainer extending transversely of said surface for releasing its liquid content upon rupture. of 'the container for spreading in the same direction lengthwise of said surface, each said container being separated from the container nextadjacent thereto on the discharge side thereof by a predetermined distance which includes .a first area on said surface extending from the liquidreleasing mouth of the container toward said adjacent container and a second and smaller area on said surface continuing toward said adjacent container and joining the end of said first surface area closest to said next adjacent container, each container holding liquid in an amount in excess of that required to cover the first-mentioned surface area with which it is associated whereby the second surface area provides a liquid-receiving portion for the excess liquid, a plurality of difficultly compressible members, at least one difficultly compressible member associated with each excess liquid-receiving portion of said support and mounted on a surface of said sheet support at a position thereon so that said difficultly compressible member and said excess liquid-receiving portion are in superposed relation, each said dihicultly compressible member extending outwardly from the surface on which it is mounted and occupying an area thereonwhich is smaller than the area of the.

excess liquid-receiving portion with which itis associated, means being provided by each said diificultly compressible member whereby pressure applied transversely of said sheet support to opposite surfaces thereof at each part of said support which includes an excess liquid-receiving portion is transmitted substantially only to the difiicultly compressible member and the part of said sheet support in superposed relation thereto.

8. The product of claim '7 wherein another sheet support is associated with said product, one of said sheet supports including a photosensitive silver halide layer of sufiicient area to provide a plurality of photosensitive image areas equivalent to said predetermined areas over which said liquid is adapted to be spread.

9. A photographic product comprising an elongated sheet having a silver halide photosensitive layer on one surface thereof, and a plurality of pairs of diflicultly compressible members mounted on a surface of said sheet, one difficultly compressible member of each pair being located adjacent one longitudinal margin of said sheet and the other diflicultly compressible member of each pair being located adjacent the other longitudinal margin of said sheet, the diIncult-ly compressible members of each pair being aligned with each other in a direction transversely of said sheet, said pairs of difiicultly compressible members being spaced apart in a direction longitudinally of said sheet by substantially similar intervals which are equal to a distance greater than the width of said sheet, the difficultly compressible members adjacent each margin of said sheet being aligned longitudinally of said sheet, each said difficultly compressible member extending outwardly from the surface on which it is mounted and occupying an area thereon which is small compared to the surface area of the sheet located between adjacent pairs of dinicultly compressible members, each. pair of difiicultly compressible members providing means whereby pressure applied to opposite surfaces of said sheet and transversely thereof in alignment "with a pair of difiicultly compressible members is transmitted substantially only to the last-named pair of difiicultly compressible members and that part of said sheet in superposed relation thereto.

10. A photographic product comprising a first liquid-confining layer, a photosensitive material capable of having a photographic record formed therein upon photoexposure and supported upon said first liquid-confining layer, said photosensitive material extending longitudinally and transversely of said first liquid-confining layer and having a portion which provides an image area, a second liquid-confining layer superposable on said first liquid-confining layer so that said photosensitive material is located between said liquid-confining layers, said second liquidconfining layer being provided with an image area similar to the first-mentioned image area, a rupturable container holding a liquid, said container being mounted to extend transversely of one of said layers at a location adjacent one end of the image area of the layer upon which it is mounted, means for holding said two liquidconfining layers together with said image areas located in overlying relation and With said container positioned between said layers adjacent a common end of said image areas, whereby said liquid-confining layers may be superposed and urged substantially into contact with each other by pressure-applying means which apply pressure to the outer surfaces of said liquid-confining layers and through which said product is movable for effecting the rupture of said container and the release and spreading of its liquid between said liquid-confining layers, said container holding liquid in an amount in excess of that required to cover said image areas whereby a portion of each liquid-confining layer at a location adjacent the end of each said image area furthest removed from said container provides a surface for receiving the excess liquid, each excess liquid-receiving portion of each said liquid-confining layer being smaller in area than each said image area, means for relieving the pressure applied to the outer surfaces of said liquid-confining layers over a part at least of said excess liquid-receiving portions to permit said excess liquid to collect therebetween, said means comprising at least one difficultly compressible member fixed to one surface of one of the liquidconfining layers and extending outwardly from said surface, said difiicultly compressiblemember having an area smaller than an excess liquidreceiving portion and being located in superposed relation to the excess liquid-receiving portion of the liquid-confining layer upon which it is mounted, said product containing a photographic reagent adapted to participate in transforming a photographic record of said photosensitive material to a picture image, said reagent being rendered effective for transforming said photographic record by liquid permeated into said photosensitive material from said container, and said photosensitive material comprising a salt of the class consisting of (a) the photosensitive dichromates; (b) the photosensitive diazonium salts; and heavy metal salts capable of forming a latent image upon photoexposure and capable of development to produce a visible image comprising the metal of said salt,

11. A photographic product comprising a first liquid-confining layer, a silver halide emulsion coated on said first liquid-confining layer to extend longitudinally and transversely of said first liquid-confining layer and having a portion thereof which provides an image area, a second liquid-confining layer superposable on said first liquid-confining layer so that said silver halide emulsion is located between said liquid-confining layers, said second liquid-confining layer being provided with an image area similar to the firstmentioned image area, a rupturable container holding a liquid, said container being mounted to extend transversely of one of said layers at a location adjacent one end of the image area of the layer upon which it is mounted, means for holding said two liquid-confining layers together with said image areas located in overlying relation and with said container positioned between said layers adjacent a common end of said image areas, whereby said liquid-confining layers may be superposed and urged substantially into contact with each other by pressure-applying means which apply pressure to the outer surfaces of said liquid-confining layers and through which said product is movable for effecting the rupture of said container and the release and spreading of its liquid between said liquid-confining layers, said container holding liquid in an amount in excess of that required to cover said image areas whereby a portion of each liquid-confining layer at a location adjacent the end of each said image area furthest removed from said container provides a surface for receiving the excess liquid, each excess liquid-receiving portion of each said liquid-confining layer being smaller in area than each said image area, means for relieving the pressure applied to the outer surfaces of said liquid-confining layers over'a part at least of said excess liquid-receiving portions to permit said excess liquid to collect therebetween, said means comprising at least one difiicultly compressible member fixed to one surface of one of the liquid-confining layers and extending outwardly from said surface, said difiicultly compressible member having an area smaller than an excess liquid-receiving portion and being located in superposed relation to the excess liquid-receiving portion of the liquid-confining layer upon which it is mounted, said product containing a silver halide developer soluble in said liquid and in an amount sufficient to develop a latent image in said silver halide emulsion, said developer being rendered effective by liquid permeated into said silver halide emulsion from said container.

12. A photographic product as defined in claim 11 wherein said difficultly compressible member comprises a porous material positioned on the image area side of the liquid-confining layer upon which said difficultly compressible member is mounted, said porous material being adapted to absorb liquid in excess of that spread over said image areas.

13. A photographic product as defined in claim l-l wherein said difficultly compressible member is carried on that surface of a liquid-confining layer which includes the image area of said layer.

14. A photographic product as defined in claim 11 wherein the means for relieving the pressure applied to the outer surfaces of said liquidconfining layers comprises a plurality of difficultly compressible members spaced apart in a direction transversely of the liquid-confining layer upon which they are mounted, said difiicultly compressible members being located on that surface of said one liquid-confining layer which includes the image area thereof.

15. A photographic product as defined in claim 11 wherein said difficultly compressible member extends outwardly from the surface of the liquid- 17 confining layer on which it is mounted by a distance which is thicker than a film adapted to be formed by the liquid from said container when the liquid is spread over the image area of said layer.

16. A photographic product as defined in claim 11 wherein said means for relieving the pressure applied to the outer surfaces of said liquid-com fining layers comprises a pair of difficultly compressible members positioned in spaced-apart relation with one dimcultly compressible member adjacent each margin of the 1iquid-confining layer upon which they are supported.

17. A photographic product as defined in claim ll wherein said means for relieving the pressure applied to the outer surfaces of said liquid-confining layers comprises a plurality of difificultly compressible members secured to that surface of one of said liquid-confining layers adapted to be brought into superposed relation with the other liquid-confining layer, each said difficultly compressible member having a thickness dimension which is greater than the thickness of the layer of liquid adapted to be spread from the container contents over the image areas of said product.

18. A photographic product as defined in claim 11 wherein the liquid in said container includes an organic film-forming material and the excess liquid-receiving portion includes a soluble reagent capable of increasing the insolubility of said organic film-forming material.

19. A photographic product as defined in claim 11 wherein said product also contains a silver halide solvent.

20. A photographic product comprising an elongated sheet support, said sheet support being provided with a plurality of perforations which are positioned to surround an area on one surface of said support located within the margins of said sheet support, said area surrounded by said perforations being adapted to have aphotographic image formed thereon by transfer, a rupturable container holding a liquid and mounted upon said surface to extend thereacross in a position adjacent one end of said area for releasing its liquid over said area upon rupture of said container by the application of pressure to opposite sides thereof, and a pair of relatively small and solid members formed of a material which is dimcultly compressible under the pressure required to rupture said container, said members being mounted on said surface adjacent opposite margins of said sheet support and substantially aligned across said sheet support outside of said area and adjacent the opposite corners of said area which are located at the end of said area furthest from said container, the diilicultly compressible members extending outwardly from said surface for a short distance and occupying an area on said surface which is considerably smaller than said image area.

21. A photographic product comprising an elongated sheet support, a portion of said sheet support lying within the margins of said support providing a tear-out portion separable from the remainder of said sheet support and which provides an image area adapted to have a photographic image formed thereon by transfer, means detachably connecting the margins of said tearout portion to said sheet support, said connecting means being readily rendable whereby said tear-out portion is separable as a unit from the remainder of said sheet support by rending said connecting means, a rupturable container holding a liquid and mounted upon one surface of said sheet support to extend thereacross in a position adjacent one end of said area for relea ing its liquid over said area upon rupture of said container by the application of pressure to opposite sides thereof, and a pair of relatively small and solid members formed of a materiai which is difficultly compressible under the pressure required to rupture said container, said members being mounted on said surface adjacent opposite margins of said sheet support and substantially aligned across said sheet support cut side of said area and adjacent the opposite corners of said area which are located at the end of said area furthest from said container, the diiiicultly compressible members extending outwardiy from said surface for a short distance and ocupying an area on said surface which is considerably smaller than said image 22. A photographic product as defined in claim 21 wherein said product contains a photographic reagent from the class consisting of the silver halide developers and the silver halide solvents, said reagent being soluble in said liquid being rendered effective upon rupture of said container and the spreading of said liquid over said image area.

23. A photographic product comprising an elongated flexible sheet providing an imagereceptive material employable in a photographic transfer process of the character wherein soluble silver complexes are transferred from a photosensitive layer to said image-receptive material for providing a positive image, said sheet having adjacent one surface thereof a silver precipitating stratum which includes said surface and which extends depthwise of the sheet from said surface, said stratum comprising a silver precipitating agent dispersed among colloidal particles of silica, said silver precipitating agent being effective in the precipitation of the silver of said complexes, said sheet also being provided with a plurality of perforations which are positioned to surround an area on said surface of said sheet located within the margins of the sheet, said area surrounded by said perforations being substantially uninterrupted and plane and being adapted to have said positive image formed therein by transfer, and a pair of relatively small and solid members formed of a difiicultly compressible material and mounted on said surface adjacent opposite margins of said sheet and substantially aligned across said sheet at positions outside of said area and adjacent opposite corners of said area at one end thereof, said difiicultly compressible members extending outwardly from said surface for a short distance and occupying an area on said surface which is considerably smaller than said image area.

24. A photographic product as defined in claim 23 wherein said sheet comprises baryta paper. References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 836,688 Johnson Nov. 27, 1906 841,699 Lawson Jan. 22, 1907 927,543 Irvin July 13, 1909 1,826,695 Favour Oct. 6. 1931 2,088,068 Ovenbaugh July 27, 1931 2,209,914 Gerber July 30, 1940 2,358,246 Nicolle Sept. 12, 1944 2,537,732 Angus Jan. 9, 1951 FOREIGN PATENTS Number Country 1 Date 815,877 France Apr. 19, 1937 

1. A PHOTOGRAPHIC PRODUCT COMPRISING A SHEET SUPPORT, A RUPTURABLE CONTAINER HOLDING A LIQUID, SAID CONTAINER BEING MOUNTED ON ONE SURFACE OF SAID SUPPORT TO EXTEND TRANSVERSELY OF SAID SURFACE FOR SPREADING OF ITS LIQUID CONTENT LENGTHWISE OF SAID SURFACE UPON RUPTURE OF THE CONTAINER, SAID SURFACE HAVING SAID CONTAINER MOUNTED THEREON BEING PROVIDED WITH AN AREA WHICH EXTENDS FROM SAID CONTAINER LENGTHWISE OF SAID SUPPORT FOR A PREDETERMINED DISTANCE AND OVER WHICH LIQUID FROM SAID CONTAINER IS ADAPTED TO BE SPREAD, SAID LIQUID BEING IN A QUANTITY MORE THAN SUFFICIENT TO COVER SAID AREA UPON RUPTURE OF SAID CONTAINER AND THE SPREADING OF SAID LIQUID UPON SAID SURFACE, SAID SHEET SUPPORT HAVING A PART THEREOF WHICH EXTENDS SAID SURFACE BEYOND THE END OF SAID AREA FURTHEST REMOVED FROM SAID CONTAINER TO PROVIDE A PORTION ON SAID SURFACE FOR RECEIVING LIQUID IN EXCESS OF THAT NEEDED TO 